The present invention concerns a method of severing useful lengths interconnected through small fillets in a sheet of paper, paperboard, pasteboard or the like, as well as apparatus for carrying out such a method.
The severing of useful lengths still interconnected after the actual punching operation by the aforesaid small fillets has heretofore been effected somewhat in the manner that a matrix with knifelike ridges was arranged at the underside of a sheet containing the useful lengths, the knifelike ridges extending along the separating lines or punched sides of the useful lengths. The sheet was pressed in a downwards direction from above this matrix so that the knifelike ridges gripped along the separating lines between the useful lengths and thus could destroy the small fillets. Special pressure fingers acting downwards from the upper side of the sheet were provided for pressing down the sheet on to the separating matrix. That made it necessary to make a special separating matrix for each pattern of cutting, which is to be considered as disadvantageous also insofar as the costs for such a matrix are not inconsiderable and may lie in the order of magnitude of $2000.
There is known from West German Patent Specification 2,310,021, as laid open to inspection, apparatus for separating useful lengths which are interconnected through small fillets, in which apparatus the adjacent useful lengths are held between upper and lower conveying devices and then simply drawn apart by these so that the fillets are broken. The conveyor units are displaceable transverse to the direction of movement of the products to be taken off, so that in this case, adaptation to the form of the products at any time is possible. The separating device, according to West German Patent Specification 2,310,021 as open to inspection, makes it possible therefore to offer what is basically a universal application which, however, requires in practice, a considerable amount of additional space and, moreover, a large technical expenditure so that high production costs which may amount to $60,000 arise, whereby an economical utilization is frequently prohibited as a matter of course. Added to this is the comparatively complicated construction of the known separating device which naturally makes necessary considerable continuous maintenance work.